55 



Anomalies. The calyx an3 corolla are distiuguisliable \n Rhipsalis, 

 which is also said to have its seeds attached to a central placenta. 



Essential CHARACTEn Sepals numerous, usually indefinite, and confounded with 



the petals, either crowning the ovarium, or covering its whole surface. Petals numerous, 

 usually indefinite, arising from the orifice of the calyx, sometimes irregular. Stamens inde- 

 finite, more or less cohering with the petals and sepals ; filaments long, filiform ; anthers 

 ovate, versatile. Oyan?<m fleshy, inferior, 1 -celled, with numerous ovula arranged upon 

 parietal placentae, equal in number to the lobes of the stigma ; style filiform ; stigmata nu- 

 merous, collected in a cluster, /"jvij^ succulent, 1 -celled, many-seeded, either smooth, or 

 covered with scales, scars, or tubercles. Seeds parietal, or, having lost their adhesion, nest- 

 ling in pulp, ovate or obovate, without albumen ; embryo either straight, curved, or spiral, 

 with a short thick radicle ; cotyledons flat, thick, foliaceous, sometimes almost obsolete (in 



the leafless species) Succulent shrubs, very variable in form. Stems usually angular, or 



two-edged, or foliaceous. Leaves almost always wanting; when present, fleshy, smooth, 

 and entire or spine-like. Flowers either showy or minute, usually lasting only one day or 

 night, always sessile. 



Affinities. It has been already remarked, on more than one occasion, 

 in this work, that the state of anamorphosis, or, in other words, that remarkable 

 distension or increase of the cellular tissue of vegetables, from which the 

 name of succulent is derived, is no indication of natural affinity, but rather 

 to be considered a modification of structure which may be common to all 

 tribes. Hence the immediate relationship of Cacteoe is neither with Euphorbia- 

 cesBjUor Laurine8e,nor Asclepiadese, nor Ficoideee, nor Portulaceas, nor Aspho- 

 delese, all of which contain a greater or less number of succulent genera ; 

 but with Grossulacespjin which no tendency whatever to anamorphosis exists. 

 The distinction between the tvvo orders is mentioned under Grossulacese. 

 Through Rhipsalis, which is said to have a central placenta, Cactese are con- 

 nected witli Portulacese, to which also the curved embryo of the section of 

 Opuntiacese probably indicates an approach. DecandoUe further traces an 

 affinity between these plants and Ficoidete. For an elaborate account of 

 this order, see his memoir above quoted. 



Geography. America is the station of the order ; no species appearing 

 to be natives of any other part of the world ; in that country they are abund- 

 ant in the tropics, extending a short distance beyond them, both to the 

 north and the south. DecandoUe states that 32° or 33° north latitude is 

 the northern limit of the order ; but it is certain that a species is either wild or 

 naturalised in Long Island, in latitude 42° north, and that there is another 

 somewhere about 49°, in the Rocky mountains. The species which are said 

 to be wild or naturalised in Europe, Mauritius, and Arabia, have been intro- 

 duced from America, and having found themselves in situations suitable to 

 their habits, have taken possession of the soil like actual natives : in Europe 

 this does not extend beyond the town of Final, in 44° north latitude. There 

 is no reason for supposing that the modern Opuntia is described in Theo- 

 phrastus, as Sprengel asserts ; the description of the former writer applying, 

 as far as it applies to any thing now known, rather to some tree like Ficus 

 religiosa. Hot, dry, exposed places are the favourite stations of Cacteee, for 

 which they are peculiarly adapted, in consequence of the small quantity of 

 evaporating pores which they possess, as compared with other plants ; a cir- 

 cumstance which, as DecandoUe has satisfactorily shewn, will account for 

 the excessively succulent state of their tissue. 



Properties. The fruit is very similar in its properties to that of Gros- 

 sulaceae, some being refreshing and agreeable to the taste, others mucilaginous 

 and insipid; they are all, however, destitute of the excessive acidity of some 

 gooseberries and currants. The fruit of Cactus opuntia has the property of 

 staining red the urine of those who eat it. The juice of Cactus manimillaris 

 is remarkable for being slightly milky, and at the same time sweet and insi[)id. 



